The present invention relates to a rigid or inflatable nautical vehicle which is propelled by a twin-paddled device. This device is actuated by a totally submerged crank gear with hollow legs which are of a disc-shaped form, the axis of which is connected to a mechanism which imparts a regular and continuous, undulating movement to two rods which each slide in a tube supporting the aquatic paddles which effect, by transmission of the aforementioned movement, a beating in parallel and in the opposite direction in the same vertical plane.
Nautical vehicles of this type traditionally comprise a floating support, comparable to a pole, to which the user is strapped, which in the event of an abrupt reversal can pose a danger to said user. The projecting parts of these vehicles can likewise pose a danger in choppy water conditions to swimmers situated in the vicinity. Corresponding propulsion systems of the same type, comprising a crank gear and a single- or twin-paddled device which are totally submerged, are produced either on the principle of a scull driven by a crank gear with a rectilinear action or by aquatic paddles which are attached directly on the actual pedals. In the first case, the force required to produce a to and from movement of the pedals is significant; in the second case, the propulsion effect of the paddles is reduced because of a beating which is of an elliptical type and not in the opposite direction, effected in the same vertical plane, following the example of that produced by humans and recognised as the most efficient.
The following nautical vehicle permits these disadvantages to be remedied.
It comprises a rigid or inflatable float which is completely or partially associated with a twin-paddled propulsion system which is actuated by a crank gear with hollow legs which are of a disc-shaped form and the pedals of which likewise comprise an adequate flexible protection. The float, having rounded shapes, is recessed on its rear part in order to allow the user to sit in a straddle position. The parts adjoining this recess comprise a slight elevation towards the front, an elevation which is more accentuated towards the rear and takes the place of a seat back, thus facilitating a position of the body which is bent in the direction of travel whilst efficaciously maintaining the lower part of the back without a special fixed attachment; the user, in a position bent towards the front, has the possibility of holding onto two handles which are attached to each side of the float in order to maintain his balance better. Steering is ensured by immersing the hand on the desired side with the palm vertical. The upper rear part contributes to the buoyancy; a fixed or removable fairing, protecting the propulsion system and open towards the rear in order to allow the beating of the paddles, forms the lower, rear part of the nautical vehicle. The hollow legs of the crank gear with a disc-shaped form likewise contribute to the buoyancy; they can be used furthermore as wheels for the transfer of the vehicle to dry land, which constitutes a further advantage. In this case, the vehicle is pulled by the handle, which is situated at the prow and provided for any possible attachment in the case of towing in an aquatic environment.
The twin-paddled vehicle comprises, according to a first characterising feature, a crank gear with two hollow legs which are of a disc-shaped form, with removable pedals and connected by its axle, comprising two toothed wheels, to two second wheels, likewise toothed and having a larger diameter, upon each of which there is attached laterally, in a diametrically opposite position, a pin; two rods pivot on the one hand on these pins and slide on the other hand in the interior of two tubes which are connected to the frame of the device by pivots; the aquatic paddles are attached to the end of these tubes. The four aforementioned toothed wheels comprise a reduction gearbox. Thus, when the user, in a semi-submerged position, actuates the crank gear, the retained mechanism allows the force to be reduced and communicates, by means of the sliding rods which at the level of the pins and in opposition describe one complete rotation, an alternation of movements, likewise in the opposite direction, of the two tubes on which the aquatic paddles are attached; this beating is limited to a simple pivoting movement about pivots because of the neutralisation of the pushing and pulling into to and from movements of the rods by sliding of these rods in the corresponding tubes; consequently the paddles effect a beating which is regular and in an opposite direction in the same vertical plane.
According to another embodiment, the four toothed wheels can be replaced by a connecting rod, taking the place of the axle of the crank gear, upon which connecting rod the two sliding rods pivot and are recessed upstream for this purpose. This embodiment produces the same result as the former, with the exception that the user is unable to benefit from a reduction in the deployed force.
The six attached drawings illustrate the invention. The first four relate to the propulsion mechanism, the last two to the floating vehicle which is indissociable from a better implementation of the aforementioned mechanism.